วันพฤหัสบดีที่ 21 พฤษภาคม พ.ศ. 2552

Micropile

Micropile

Micropile is another type of pile which is act as a supporting structure to transfer the load from the building to the ground. As the name implies, micropile is small diameter piles constructed by the drilling process and are often keyed into rock. There is various diameter of micropile can be found in the market ranging from 100mm to 250mm. Of late, technological advancement in machinery has made it possible for micropile of much greater diameters to be constructed.

Application of Micropile

In the past micropile was only used when the ground conditions warranted it because of considerations on cost and speed. Micropile is slow because of the drilling and flushing process, it might takes minutes or hours to complete.

But the trend is such, micropile is now gaining greater popularity and getting wider acceptance because of the requirement to comply with no noise and low vibration regulations, expecially in congested environments.

Geotechnically, micropile is most suitable in the following ground conditions :

1) Shallow Bedrock

2) Boulders and Cavities

3) Intermediate Hard Strata

4) Underpinning

How To Install Micropile

Micropile is widely used in the construction field because of the low vibration and no noise, micropile is widely used in housing area, school, hospital or any location which doesn’t allow to make noise while pile driving process. As you know, concrete pile like spun pile and reinforced concrete square pile produce high volume while driving pile. The installation procedure for micropile is almost similar to bored piling, it’s using drilling method.

1) Drilling and Flushing

2) Withdrawing Drilling String

3) Inserting Steel Reinforcement and Grouting

4) Completed Micropile

Construction Photos For Micropile

1) Micropile for underpinning an existing 4-storey office building which showed signs of settlement.

2) The workers are doing micropiling works.

3) Micropiling work in progress. A high pressure compressor is being used for flushing out the drilled materials.

4) A mini, but powerful hydraulic crawler drill which is useful for micropiling works in :a) Congested locations with extreme headroom constraint.b) Difficult hillside development where rock is encountered.